Automated system and drilling rig for continuously and automatically pulling and running a drill-pipe string



Oct. 8, 1968 VA. GHEORGHE ET AL 3,404,741

AUTOMATED SYSTEM AND DRILLING RIG FOR CONTINUOUSLY AND AUTOMATICALLYPULLING AND RUNNING A DRILL-PIPE STRING Filed Dec. 20, 1963 5Sheets-Sheet l 4 Inventors:

Gheorghe ALDEA,|OQYI NICOLAU Leon DOGARU, Ion DUMITRU #160 ATfar-ney3,404,741 LY AND STRING 5 Sheets-Sheet 2 Oct. 8, 1968 GHEORGHE ETALAUTOMATED SYSTEM AND DRILLING RIG FOR CONTINUOUS ING AND RUNNING ADRILL-PIPE Filed Dec.

AUTOMATICALLY PULL 20, 1963 .Z'rzremors: Gheors he A LDEA loan NICOLAUAfforney Oct. 8, 1968 A. GHEORGHE E AL 3 0 AUTOMATED SYSTEM AND DRILLINGRIG FOR CONTINUOUSLY AND AUTOMATICALLY PULLING AND RUNNING A DRILL-PIPESTRING Filed Dec. 20, 1965 5 Sheets-Sheet 5 fnverrtoks:

United States Patent 3 404 741 AUTOMATED SYSTEM AND DRILLING RIG FORCONTINUOUSLY AND AUTOMATICALLY PULL- ING AND RUNNING A DRILL-PIPE STRINGAldea Gheorghe, Nicolau Ioan, Dogaru Leon, and

Dumitru Ion, Campina, Rumania, assignors to Ministerul IndustrieiPetrolului si Chimiei, Bucharest, Rumania Filed Dec. 20,1963, Ser. No.332,310 Claims priority, application Rumania, Dec 28, 1962, 45,942 5Claims. (Cl. 17585) The present invention relates to an automated systemand a drilling rig for continuously performing round trips in oil or gaswells while drilling or producing. Running and pulling the drill-pipestring, casing, tubing or sucker rod strings in oil and gas wells in theconventional way is known to be time consuming. Trip operations requiremuch time particularly in deep drilling, where round trips for changingthe bit are more frequent. The total drilling time in the case of deepwells is thereby considerably increased, resulting in a higher cost. Inthese conditions crew fatigue may become excessive and accidents arelikely to occur.

To reduce the trip time and labor, conventional drilling rigs are knownto be equipped with fully mechanical devices which perform all the stepsinvolved in the trip operations. In addition there are rigs providedwith automatic means for automatically performing some of the stepsinvolved in running or pulling the drill-string. These rigs are operateddiscontinuously and they are generally designed to handle stands ofpipes, which are added or removed while the drill string is supported byslips or an elevator. These known rigs are provided with a singlehoisting device for the drill string and the derrick is relatively high.Separate mechanisms are used for the delivery, transfer and positioningof the pipe stands in the central area of the derrick, and thedisplacement of the pipe stand from the storage rack to the derrickcenter includes several kinds of correlated movements: vertical andhorizontal translating motions and swinging or rotating motions. Inthese known rigs, the cycle for running or pulling a pipe stand requiresthat a complete operating cycle be effectuated by the rig.

The main disadvantages of these fully mechanical or partially automatedrigs consist in the following: their elaborate design; the requirementof a high derrick; and their discontinuous operation, which does notpermit the trip time to be reduced by more than 30% as compared with theconventional rigs using no mechanical or automatic means.

Fully automated rigs are also known, which allow all the steps of thetrip operation to be automatically performed. The operation of theserigs is continuous and they use pipe singles for assembling thedrill-string instead of pipe stands. The pipes are being added orremoved while the drill-string is in continuous motion, at constantspeed, which makes possible for the trip operations to be performed at afaster rate, 8-10 times that of the conventional rigs. The trippingoperations can be performed at this constant speed owing to the use oftwo lifts whose movements are synchronized, which support successivelythe weight of the drill-pipe string, and the single pipe to be added orremoved is handled above the upper lift.

The automated rigs now in use, differ essentially in the design of themeans used for transferring the pipes from the pipe storage rack forpositioning the pipe for stabbing. With these rigs, a complete trip-inor trip-out cycle to run or pull the pipe requires three operatingcycles ofthe rig. Thus, the predetermined sequence of operative stepsrequires the simultaneous handling of three in- 3,404,741 Patented Oct.8, 1968 dividual pipes in the rig area: one pipe is being transferredfrom or to the storage rack, the second pipe is being made up or brokenout (joined or dismantled), and the third pipe which was made up orbroken out before, is being run in or pulled out, as part of the stringwhich is being tripped in or out in a continuous motion, at constantspeed, throughout the operation.

The disadvantage of these automated rigs lies in that they require thedelivery of the pipes to take place above the upper lift, using for thispurpose separate means to raise the pipe received from the storage rackto the upper half of the derrick, and separate means to bring it in thestabbing position, and separate means to transfer, while in motion, thedelivered pipe to the upper lift.

Due to the required special configuration of the pipe delivery means,these rigs have the disadvantage of using derricks of a height exceedingthe length of two pipes, as two end-to-end pipes must be permanentlyavailable in the derrick: one pipe is being made up in the drill stringand the other one is being transferred to the upper lift, in addition athird pipe already made up in the drill-string, is going into the hole.

These automated rigs have further the disadvantage that owing to thefact that the pipes are being delivered in this way, both lifts must befitted with slips for sup porting the drill-string which causes the slipwedges to impress twice their marks upon the pipes each time they aretripped in or out.

A further disadvantage of these known automated rigs lies in that thepipe transfer from the storage rack to the central area of the derrickor back to the storage, which occurs above the upper lift, must involvea number of synchronized translating vertical and horizontal-movements,as well as rotating movements.

It is a general object of the present invention to provide a drillingrig in which the aforedescribed disadvantages are substantiallyeliminated.

The system-according to the present invention eliminates the abovementioned disadvantages in that, for achieving trip-time reductionssimilar to those attained by the automated rigs now in use, thedrill-string is automatically run and pulled in a continuous motion bymeans of two lifts. On the trip-in operation the pipes are deliveredsuccessively in horizontal position, to the lower part of the upper liftapproximately mid-way up the derrick, where the upper lift movingupwards grips one end of the pipe while the other end is horizontallydisplaced, whereby the pipe is rotated and positioned in the centralarea of the derrick and is then being made up in the drill-string inmotion at the level of the lower lift which is moving downwards whilesupporting the drill-string. When the drill-string is tripped out, thesteps involved in the operation mentioned above are reversed.

The drilling rig according to this invention uses on the trip-inoperation a tray conveyor for picking up the pipe horizontally from thestorage rack, which is located near the derrick, thereafter said pipe istransferred to guiding track means mounted mid-way up the derrick. Anupper lift, which transfers the pipe from said guiding track means tothe central area of the derrick, carries out the transfer by means of atrolley device which is provided with a hydraulically pivotable arm.This trolley device moves along the guiding track means and the upperlift carries power swivel means equipped with an elevator, said powerswivel means and elevator rotate so that the ends of the pipe raisedfrom the storage rack are supported throughout its rotation untilpositioned in the central area of the derrick by said elevator inconjunction with said trolley device, which after centering the pipe inthe derrick changes its function by releasing its clamp jaws, the pipenow being positioned for stabbing. The make-up operation is performedwhile the drill-string is in motion, by means of a make-and-break devicemounted upon the lower lift, which is running into the drill-string in acontinuous motion at constant speed while the drill-string is beingsupported by a supporting device.

To remove the pipe in the trip-out operation, the same devices are usedto transfer the pipe to the storage rack, but the sequence of steps ofthe operation is reversed. In addition thereto the rig uses a lateraltransfer unit for laterally transferring the pipe from the guiding trackmeans mounted mid-way up the derrick, to the tray conveyor whichdeposits the pipe in the storage rack.

In the accompanying drawings there is shown for purposes of illustrationone example of a rig according to this invention in which:

FIG. 1 is a front elevation view of the rig;

FIG. 2 is a side elevational view of the rig; and

FIG. 3 illustrates diagrammatically the operating cycle of the rig.

FIGURES l and 2 illustrate the rig action while the rig is performingthe steps of the operation indicated in the operative cycle diagram ofFIG. 3.

According to the invention, the rig uses a U-shaped derrick 1, theheight of which is equal to about two lengths of drill pipe. In order toachieve the guided raising and lowering of the drill-string and of thepipe which is being delivered, an upper hydraulic lift 2 is used in theupper half of derrick 1. The upper lift 2 is actuated by hydraulictelescoping cylinders 3 of known design: a hydraulically or otherwiseactuated power swivel 4 is mounted on the upper lift 2. This arrangementenables the power swivel 4 to travel vertically in the upper half of thederrick 1. The power swivel 4 can be made to swing 90 to a horizontalposition by means of a wellknown mechanism consisting of a hydrauliccylinder slidably connected at one end to the upper lift 2, and at theother end to the power swivel 4. The maximum hydraulic cylinder strokecauses the power swivel 4 to be in a vertical position, and the shortesthydraulic cylinder stroke causes the power swivel 4 to rotate 90 to thehorizontal position. The power swivel 4 carries a hydraulically orotherwise actuated elevator member 5, which is axially mounted on thepower swivel 4 in order to ensure rotation of its two halves. Theelevator member 5 is suspended on both sides thereof so as to centrallysupport the drill-string weight. The elevator member 5 can be made toswing 90 together with the power swivel 4 so that it can be latched orunlatched around one end of the horizontal pipe positioned mid-way upthe derrick 1. In order to add a new pipe to the drill-string whiledrilling, a hydraulically or otherwise actuated make-up unit 6 is used,which can be mounted on the power swivel 4 in place of the elevatormember 5, and the pipe is then made up directly by means of power swivel4. The make-up unit 6 is a well known powered jaw tool, the jaws ofwhich are hydraulically actuated for engaging the pipe. Rotation of themake-up unit 6 for making up an additional pipe is performed by thepower swivel 4 upon which the unit 6 rests instead of the elevatormember 5.

A lower lift 7, actuated by the lower hydraulically actuated telescopiccylinders 8 of known design, guides the lowering and elevating of thedrill-string in the lower half of derrick 1. There is mounted amake-and-break unit 9 on the lower lift 7. The unit 9 is hydraulicallyor otherwise actuated and is of known design. It is positioned at alltimes axially in derrick 1 and serves to make up or break out the pipeto be added or removed, while the lifts 2 and 7 travel up and down insynchronized movements. There is secured on the lower lift 7 asupporting device 10 using slips or other means, of known design. Thedevice 10 is disposed under the make and break unit 9 and serves tosupport the drill-string while said drillstring is lowered or raised inthe lower half of derrick 1 by means of the lower lift 7.

The drill pipes which are to be delivered into the der- 14? rick 1, arehorizontally stored at the ground level on the storage rack 11,wherefrom each pipe can be delivered or received by means of tiltingloading forks 12 which are arranged so that the pipe can roll by gravityether from or towards the tray conveyor 13. The latter is provided withdouble strands of chain 14 and trays 15, or other types of known design,for raising the pipe from the storage rack 11 mid-way up the derrick 1,or for removing the pipe from mid-way up the derrick and lowering it tothe storage rack 11.

The pipe raised in horizontal position by the tray conveyor 13v mid-wayup the. derrick 1, is rotated in order to be positioned in the centralarea of derrick 1, one end of said pipe being latched in the elevatormember 5 and raised in the upper half of derrick 1, while the other endof the pipe is displaced horizontally by a trolley device 16, which isarranged to move horizontally at a level about mid-way up the derrick 1.The horizontal displacement of trolley 16 is elfectuated by a transferunit 17 which uses cable, chains or other known means along the guidingtrack 19 mounted on a supporting frame 18. While the pipe is beinghorizontally transferred, one end thereof is gripped from above by theclamp jaws 21 of the trolley arm 20 which rotates 90 while guiding saidend of the pipe to the center of derrick 1. Partial release of the clampjaws 21 of the trolley arm 20 permits the pipe to be positioned forstabbing, while the pipe is supported at its other end by the upperlift2. In the trip-out operation a lateral transfer unit 22 is used totransfer the pulled pipe, which has been placed on the guiding track 19,to the tray conveyor 13, which lowers the pipe to the storage rack 11.

A safety device 23, comprising slips or other means of known design, ismounted on the lower level of derrick 1. The safety device 23 is used inthe case a malfunction of the rig should occur.

The rig operation cycle for tripping in the drill-string, in the rigillustrated in FIGS. 1 and 2, is carried out according to the cyclediagram illustrated in FIG. 3, wherein the main steps of a completeoperating cycle of the rig in the order from a i are illustrated; in thetripout operation the sequence of steps of the operation is reversed,becoming i a. The main steps involved in the trip-in operation,illustrated in FIG. 3 relate to the three pipes which are beingsimultaneously handled in the derrick: pipe A which is being transferredfrom the storage rack 11 to the guiding track 19; pipe A which is beingtransferred from the guiding track 19 to the center area of derrick 1 tobe made up in the drill-string, and pipe A already made up in thedrill-string which moves into the hole in a continuous motion. The maincomponents described and denoted according to FIG. 1 and 2 perform thefollowing steps forming the operation cycle of the rig:

Step (a).The upper lift 2 with thepower swivel 4 and the elevator member5 continue their descending motion, supporting the drill-string, wherebypipe A is run in; the lower lift 7 with the make-and-break device 9 andthe supporting device 10 descend, their movements being synchronized tocorrespond to the upper lift2, and the weight of the drill-string istransferred, while in motion, to the supporting device.10; the trolleydevice 16 with its arm 20 remain for the time being stationary; the trayconveyor 13 moves the pipe A to the. guiding track 19 located mid-way upthe derrick 1.

Step (b).The upper left 2 with the power'swivel, 4 and the elevatormember 5 descend, their movements being synchronized to correspond tothat of the. lower lift 7, at the same time. the elevator member 5 isbeing unlatched; the lower lift ,7 descends together. withthe makeand-break unit 9 and the supportjng' device 10.which supports and lowersthe drill-string together with pipe-A the trolley arm 20 grips pipe Awhichv has beenr'raisednmid way up the derrick 1; the tray conveyor 13starts .lifting the next pipe A picked up from the storage rack 11.

Step (c) .The upper lift 2 with power swivel 4 and elevator member arestationary and the power swivel 4 together with elevator member 5 rotate90 and thereafter latch elevator member 5 around pipe A which has beendelivered to the guiding track 19; the lower lift 7 descends furthertogether with the make-and-break device 9 and the supporting devicewhich still supports the drill-string, lowering said drill-stringtogether with pipe A the transfer unit 17 is stationary together withthe trolley 16 whose arm 20 grips pipe A which has been raised mid-wayup the derrick 1; the tray conveyor 13 goes on lifting the next pipe AStep (d).--The upper lift 2 with power swivel 4 and elevator member 5rise rapidly, the elevator member 5 gripping one end of pipe A which isbeing elevated in the upper half of the derrick 1; the lower lift 7continues descending together with the make-and-break device 9 and thesupporting device 10 which still supports the drillstring, lowering ittogether with pipe A the transfer unit 17 displaces the trolley 16, thearm 20 of which is gripping one end of pipe A the tray conveyor 13continues raising the next pipe A Step (e).-The upper lift 2 continuesto rise rapidly with power swivel 4 and elevator member 5 which supportsone end of pipe A on arriving at the top of its stroke, the upper lift 2reverses motion and begins to descend, the movement of said upper lift 2being synchronized to correspond to that of the lower lift 7, whichcontinues its descent, together with the supporting device 10 whichstill supports the drill-string thereby lowering said drill stringtogether with pipe A the transfer unit 17 stops the trolley 16, and thetrolley arm 20 which has been rotating 90", by releasing its clamp jaws21 positions pipe A in the central area of derrick 1 while said pipe Ais being lowered to be stabbed in pipe A the tray conveyor 13 is raisingnow the next pipe A Step (f).--The upper lift 2 with power swivel 4 andelevator 5 descend simultaneously with the lower lift 7, to run pipe Athe drill-string being supported by the supporting device 10; meanwhilethe make-and-break device 9 after wiping and greasing the tool-jointthread makes up pipe A (as indicated by the curved arrows) the clampjaws 21 of the trolley arm 20 are now completely released and thetrolley 16 with its arm 20 is moved back to its original position; thetray conveyor 13 is raising the next pipe A Step (g).The upper lift 2with power swivel 4 and elevator member 5 descend simultaneously withthe lower lift 7, but the weight of the drill string is transferred toelevator member 5 by disengaging the supporting device 10; the lowerlift 7 continues to descend simultaneously with the upper lift 2 whilethe supporting device 10 releases the drill-string; the trolley 16 withits arm 20 are moved to their original position by means of the transferunit 17; the tray conveyor 13 continues raising the next pipe A Step(h).The upper lift 2 with power swivel 4 and elevator member 5 continueto descend supporting now the drill-string; the lower lift 7 togetherwith the make up and break out unit 9 and the supporting device 10-reverse their motion and rise rapidly the trolley 16 with its arm 20remain stationary in their original position; the tray conveyor 13continues raising the next pipe A Step (i).The upper lift 2 with powerswivel 4 and elevator 5 descend and support the drill-string; the lowerlift 7 with the make-and-break device 9 and the supporting device 10reverse their motion and descend rapidly to move jointly with the upperlift 2. The trolley 16 with its arm 20 and the transfer unit 17 arestationary; the tray conveyor 13 raises pipe A and deposits it On theguiding track 19.

On the trip-out operation the steps sequence described above isreversed, abeing per-formed in the order i a.

At the same time, Step a involves a lateral transfer unit 22, serving toremove pipe A from the guiding track 19 to the tray conveyor 13. Thelateral transfer unit remains stationary throughout the trip inoperation. The storage rack 11 which was delivering pipes to the derrickfor the tripping-in operation, changes now to receive the pulled pipes,by setting the tilting loading forks 12 so that the pipe A which isbeing removed, can roll by gravity through the storage rack 11. t

For drilling, the drill-string is made up in the power swivel 4 whichmoves together with the upper lift 2 in the upper half of the derrick,while the lower lift 7 is stationary. In the case of bottom powerdrilling the power swivel is used as a conventional swivel.

Adding of a new pipe while drilling, is accomplished by means of thepower swivel 4 eliminating thus the need for the kelly, which isgenerally required for the conventional rotary tables. The power swivel4 serves to make up directly the pipes to be added in its tool-joint,thus no separate make up device is necessary. However, the elevatormember 5 must be replaced by the make up device 6 before adding a newpipe. The bit is made up either separately on the storage rack 11 or inthe derrick 1, at the level of the lower lift 7.

Casing running operations are similar to those performed to run in thedrill string.

In order to perform fishing jobs, the automated operation of the rig isswitched off and the upper lift 2 can be independently controlled, sothat the fishing job can be conducted in the conventional way.

To perform the steps sequence of the rig operation according to thecycle-diagram of FIG. 3, the operation of each device of the rig isautomatically programmed. In special cases, for example: the malfunctionof the automated devices of the rig or when fishing jobs or remedialworks are necessary, the component devices of the rig can be controlledindependently. As the component parts of the automatic drilling rig arehydraulically actuated, their being placed in operation or being stoppedrequires handling, in a well-known manner, of inlet and outlet valvescontrolling the pressure fluid that actuates them. The inlet and outletvalves are controlled either hydraulically or electrically, according tothe automatic programmer type in use. Switching on and off of eachcomponent part, necessary for the drilling rig automatic control, occursaccording to the operation cyclogram of the automatic drilling rig. Allthe inlet and outlet valves are thus opened or closed from the automaticprogrammer. In the case of electrically actuated valves, the automaticprogrammer will be a well-known multiswitch mechanism, and in case ofhydraulically actuated valves the automatic programmer will also be awell-known multidistributor mechanism. For individually handling thedrilling rig devices, each inlet and outlet valve can be controlledindependently, as required without using the automatic programmer.

The advantages of the method and rig, according to the presentinvention, are as follows:

The rig described in the present invention allows the trip time to bereduced by an amount similar to that achieved by the known automatedrigs, however it is simpler than the latter because it has no separatetransfer devices to displace the pipe in the upper half of the derrick,no separate devices to center the pipe in the derrick, no separatedevices for transferring the delivered pipe, while in motion, to theupper lift;

The rig uses a derrick of reduced height;

In tripping in or out the drill string, the slip wedges of thesupporting device impress their marks at most only once on each pipe;

The number of movements involved in delivering the pipe from the storagerack to the center area of the derrick is reduced;

Rig operation is shockless and vibrationless, each pipe being supportedat both ends throughout its delivery;

Many modifications and adaptions will become readily apparent to personsskilled in the art and for that reason it is intended that thisinvention be limited only by the 7 appended claims as interpreted in thelight of the prior art.

What is'claimed is:

1. System for'continuously and automatically performing round tripoperations on oil and gas wells while drilling or in production, thedrilling string consisting of pipes assembled by means of two liftswhose movements are synchronized, said system involving for the transferof each pipe to be added to the drill-string successively, raising ofthe pipe in horizontal position from the storagerack to a mid-waystation up the derrick, 90 swinging of the pipe to vertical position inthe central area of the derrick, whereby one end of the said pipe isdirectly gripped by the upper lift during its upward movement so as toraise said pipe end to the upper section of the derrick, while the otherend of said pipe is being horizontally translated, whereafter said pipeis lowered along the derrick axis at a speed such as to catch up withthe drill-string which is continuously descending and thereaftersynchronization of said pipe speed with the constant descending speed ofthe drill-string, rotation of said pipe for its making up at the levelof the lower lift, while both said pipe and drill-string arecontinuously descending, when coming out of the hole the movements arereversed.

2. Rig for continuously and automatically performing the round tripoperations on oil and gas wells while drilling or in production, servingto apply the system set forth in claim 1, said rig comprising for thetrip-in operation, a tray conveyor which successively picks up the pipesfrom a storage-rack placed upon the ground near the derrick, saidstorage-rack being equipped with tilting loading forks for continuouslydelivering pipes by gravity to said tray conveyor which deposits thehorizontally raised pipe onto a guiding track positioned mid-way up thederrick, said guiding track supporting a trolley equipped with an armfor the gripping and guiding in horizontal position one end of saidpipe, the other end of said pipe being then gripped by the upper lift toswing said pipe 90 and bring it into the central area of the derrick,said upper lift being equipped for this purpose with a power swivel andan elevator, said power swivel and elevator being hydraulically actuatedto laterally swing 90, while one end of the pipe being delivered issupported and vertically moved along the derrick axis by said elevatormounted on said power swivel of said upper lift, and the other end ofsaid pipe is horizontally moved along the guiding track by means of saidarm of said trolley, in addition said arm by releasing its clamp jawspermits positioning of said delivered pipe for stabbing, the make upoperation being performed by means of a make-and-break device located onthe lower lift which runs continuously the drill string into the hole atconstant speed, said drill string being supported by a supporting deviceprovided in the lower lift.

3. Rig as described in claim 2, comprising in addition for the trip outoperation a lateral transfer unit which transfers laterally the pipefrom the guiding track located approximately mid-way up the derrick to atray conveyor which takes the pipe away to the storage rack, where the 8tilting loading forks a're'now set to permit the pipe to roll by gravityto the storage rack.

4. A method of continuously and automatically running in or pullingout'a drill pipe string consisting of a plurality of connected "drillpipe sections in oil'and gas wells, by means of a ri having two separatelifts the movements of which are synchronized with respect to eachother, comprising the steps 'of' adding adrill'plpe section by raisingsaid section in a horizontal position from a storage rack located atthefoot of said rig to a level substantially midway up said rig,pivoting said pipe section to a vertical position in the central area ofsaid rig, said pivoting movement being effectuated by gripping one endof said pipe section with means connected to the upper lift of said twoseparate lifts during the upward movement thereof while gripping theother end of said pipe section and horizontally transferring it towardsthe center of said rig, thereafter lowering said pipe section by meansof said upper lift at a speed adapted to catch up with said pipe stringwhich is continuously descending at constant speed and which is beinglowered by the lower lift of said two separate lifts, thereaftersynchronizing the speeds of said descending drill pipe string and saiddescending drill pipe section, and rotating said pipe section therebyjoining it to the upper end of said drill pipe string while both saiddrill'pipe string and said pipe section are descending at equal speeds.

5. A drilling rig for continuously and automatically running in orpulling out a drill pipe string in oil and gas wells, consisting of aplurality of drill pipe sections, comprising in'cornbination, a righaving upper and lower hydraulic lift means adapted to selectivelysupport said drill pipe string and move in synchronized movements withrespect to each other, conveyor means mounted adjacent to said rig andadapted to transport successively individual drill pipe sections in ahorizontal position to a level within the operative range of said upperhydraulic lift means, a hydraulic pipe section handling mechanismoperatively mounted in said upper hydraulic lift means for transferringsaid transported pipe section from a horizontal position to a verticalposition in axial alignment with said rig, and pipe-sectionmake-and-break means operatively mounted in said lower hydraulic liftmeans for selectively joining or disjoining a pipe section to said drillpipe string.

References Cited UNITED STATES PATENTS Simmonds -85 X CHARLES E.OCONNELL, Prim'ary Examiner.

RICHARD E. FAVREAU, Assistant Examiner.

1. SYSTEM FOR CONTINUOUSLY AND AUTOMATICALLY PERFORMING ROUND TRIPOPERATIONS ON OIL AND GAS WELLS WHILE DRILLING OR IN PRODUCTION, THEDRILLING STRING CONSISTING OF PIPES ASSEMBLED BY MEANS OF TWO LIFTSWHOSE MOVEMENTS ARE SYNCHRONIZED, SAID SYSTEM INVOLCING FOR THE TRANSFEROF EACH PIPE TO BE ADDED TO THE DRILL-STRING SUCCESSIVELY, RAISING OFTHE PIPE IN HORIZONTAL POSITION FROM THE STORAGERACK TO A MID-WAYSTATION UP THE DERRICK, 90* SWINGING OF THE PIPE TO VERTICAL POSITION INTHE CENTRAL AREA OF THE DERRICK, WHEREBY ONE END OF SAID PIPE ISDIRECTLY GRIPPED BY THE UPPER LIFT DURING ITS UPWARD MOVEMENT SO AS TORAISE SAID PIPE END TO THE UPPER SECTION OF THE DERRICK, WHILE THE OTHEREND OF SAID PIPE IS BEING HORIZONTALLY TRANSLATED, WHEREAFTER SAID PIPEIS LOWERED ALONG THE DERRICK AXIS AT A SPEED SUCH AS TO CATCH UP WITHTHE DRILL-STRING WHICH IS CONTINUOUSLY DESCENDING AND THEREAFTERSYNCHRONIZATION OF SAID PIPE SPEED WITH THE CONSTANT DESCENDING SPEED OFTHE DRILL-STRING, ROTATION OF SAID PIPE FOR ITS MAKING UP AT THE LEVELOF THE LOWER LIFT, WHILE BOTH SAID PIPE AND DRILL-STRING ARECONTINUOUSLY DESCENDING, WHEN COMING OUT OF THE HOLE THE MOVEMENTS AREREVERSED.